How bad could this have been?

[sidechoke67]

Bringing my boat back in yesterday morning, about 25 yards from the launch, and I hear a loud pop, and the motor sounds a lot louder, and definitely "off". Luckily, we were close enough that I could shut the engine off immediately and coast in to the dock. When I get home, I look and discover that I popped a spark plug, and it landed against the fuel line (fuel line in yellow). The line was *almost* all the way melted through from the couple of seconds the spark plug sat there before I shut the engine off.

Now I'm curious what could have happened if the firing spark plug had melted all the way through the fuel line. The boat is a Glastron 175 open bow, with a 3.0L Volvo (carbureted) engine. The fuel line connects the fuel filter to the carburetor. I'm sure that nothing good would have happened if the plug had melted all the way through - but I am wondering if it would have been small fire bad, or mushroom-cloud bad ?

Thanks for any thoughts.

 

[h2odick]

Re: How bad could this have been?

Thats some scary looking "fuel" hose.. Yikes! That stuff is fuel rated? I wouldn't have water running through that line in my boat let alone fuel!
From the look of things, that could have easily ended up with you, your family, and your whole boat perishing.. Thank god nobody got hurt.
I dont know about you, but I would go and get some bonafide fuel hose. You dont also have an inline glass filter flopping around in your engine bay too do ya? :faint2:

 

[SWD]

Re: How bad could this have been?

Looks more like the sight hose that is between the fuel pump and carb. In that instance I doubt anything would have happened. If this truly is the fuel hose, then its the wrong type of hose for this application. Count yourself lucky and get this replaced with rated fuel hose and also check your other spark plugs.

 

[WIMUSKY]

Re: How bad could this have been?

A good reason to always have a fire extinguisher on board.......

 

[DAN M VAGOS]

Re: How bad could this have been?

BOOOOOOOM!!!!! I don't like the look of that hose I think you should switch to the good old black fuel line its much thicker and I have seen it get as hot as what you show and not melt.

 

[greenbush future]

Re: How bad could this have been?

Sounds like you need to go over your entire engine/boat and make sure everything is as it should be. Having a spark plug "pop" out as you suggested, isn't a good thing ever. The list of possible danger(s) is endless and and you should feel very lucky to have avoided disaster. I have never seen a fuel line that looks like the one you have shown us. It may be the right kind, but it did show some melting, who installed this and is it safe?

The idea is obviously to never get the fire extinguisher situation.

 

[Slip Away]

Re: How bad could this have been?

On his Glastron 175, that yellow line is common to the VP 3.0L motor, as seen in this picture...

 

[haulnazz15]

Re: How bad could this have been?

That yellow line is for the fuel pump failure and doesn't contain any fuel in it unless the diaphragm in the pump was ruptured. Still needs to be replaced to ensure it is up to par in the event of a fuel pump failure. To be honest though, there likelihood of a fire isn't too great even if there had been fuel in the line. The spark plug being "hot" doesn't typically ignite liquid gasoline, it takes a spark or flame to ignite the fumes. Not saying it couldn't have caught fire, it just isn't absolute certainty by any means.

 

[spdracr39]

Re: How bad could this have been?

Looks more like the sight hose that is between the fuel pump and carb. In that instance I doubt anything would have happened. If this truly is the fuel hose, then its the wrong type of hose for this application. Count yourself lucky and get this replaced with rated fuel hose and also check your other spark plugs.

This is it and it isn't supposed to have fuel in it unless something is wrong.

 

[BRICH1260]

Re: How bad could this have been?

Never heard of a spark plug busting out like that. Are you sure it was screwed in to the block properly. The threads on the plug do not appear to be damaged. Check the plug holes in the block, are the threads in the block stripped?

I would definately get some new fuel line, that does not look sufficent for a pressurized system. You were very lucky, you`ve got some work to do before you should have that boat back in the water.

 

[H20Rat]

Re: How bad could this have been?

Never heard of a spark plug busting out like that. Are you sure it was screwed in to the block properly. The threads on the plug do not appear to be damaged. Check the plug holes in the block, are the threads in the block stripped?

I would definately get some new fuel line, that does not look sufficent for a pressurized system. You were very lucky, you`ve got some work to do before you should have that boat back in the water.

I've seen plugs work themselves out, it actually isn't that uncommon. Temperature cycling + vibration + low recommended torque, and out it comes.

As far as the hose, that isn't a pressurized system. Its a worst-case overflow that vents it back into the tank (or sometimes into the bilge!) if the diaphram in the carb fails. Many non-marine carbed vehicles have similar systems that just toss the fuel overboard if it happens. Better than dumping fuel all over the hot engine and exhaust manifold.

 

[UncleWillie]

Re: How bad could this have been?

That hose is made of TYGON. Really Tough Stuff!
It is CARB Approved for Small Engine fuel ines.
Commonly seen on Weed Whackers and Leaf Blowers.

Check the other Plugs. It looks like that Plug Fell Out, rather than Blew Out!

 

[gm280]

Re: How bad could this have been?

I concur with UncleWillie. That line looks like TYGON fuel line and is very good quality. It does meet all CARB standards and it is used in many types of lawn maintenance equipment and basically any engine that uses mixed fuels or Ethanol fuels. So I don't see anything wrong with using it myself. This is an unusual situation and certainly not a forgotten maintenance issue OR use of sub-quality fuel line. Of course it could have been worst, but seriously would of and could of is not what it actually was... Glad things turned out for the better... Replace the parts and happy boating...again...

 

[sidechoke67]

Re: How bad could this have been?

Thanks for the responses everyone! I feel somewhat better knowing that line wouldn't ordinarily be carrying fuel.

Lots of great advice given - other plugs were all tight, by the way.

Thanks again!